Illustration of WASP-18
The artist's illustration depicts a star and its planet, WASP-18b, a giant exoplanet that orbits very close to it. A new study using Chandra data has shown that WASP-18b is making the star that it orbits act much older than it actually is. (Credit: Illustration: NASA/CXC/M.Weiss)

X-ray & Optical Images of WASP-18
The right image reveals that no X-rays of the WASP-18 system were detected during a long Chandra observation. The source is visible in the optical image, left. The non-detection in X-rays is surprising given the age of the star, suggesting that the planet is weakening the star's magnetic field through tidal forces.
(Credit: X-ray: NASA/CXC/SAO/I.Pillitteri et al; Optical: DSS;)